\documentclass{article}
\usepackage[T2A]{fontenc}
\usepackage[cp1251]{inputenc}
\usepackage[english,bulgarian]{babel}
\usepackage{color}
\usepackage{pst-pdf}
\usepackage{pstricks,pst-node,pst-text,pst-grad,pst-fill,pst-eucl}
\newpsstyle{gridstyle}{subgriddiv=0,gridcolor=lightgray,griddots=10,gridlabels=7pt}

\begin{document}
\pagestyle{empty}
\psset{unit=1cm}
\begin{pspicture}[showgrid=false](0,0)(13,5.5)

%рамки
\psset{linewidth=1.5pt}
\psframe[fillstyle=solid,fillcolor=blue!40](0.5,1.5)(3.5,5)
\psframe[fillstyle=solid,fillcolor=orange!40](5,3.5)(9,5)
\psframe[fillstyle=solid,fillcolor=yellow!40](4,0.5)(10,2.5)
\psframe[fillstyle=solid,fillcolor=brown!40](10.5,1.5)(12.5,5)

%стрелки
\psset{doubleline=true,linecolor=red,arrowlength=1,linewidth=0.8mm}
\psline{<->}(3.5,1.8)(10.5,1.8)
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%дефиниране на възлите (без рамката)
\rput(2,3.3){\parbox{3cm}{
\begin{center}\large
Външно устройство
\end{center}
}}
\rput(7,4.3){\parbox{4cm}{
\begin{center}\large
Микропроцесор
\end{center}
}}
\rput(11.5,3.3){\parbox{2cm}{
\begin{center}\large
RAM
\end{center}
}}
\rput(7,1.2){\parbox{6cm}{
\begin{center}\large
Блок директен достъп до паметта
\end{center}
}}
\rput(7,2.2){\parbox{6cm}{
\begin{center}\large
DMA
\end{center}
}}
\end{pspicture}
\end{document}
